Flash memories known as small-sized storage devices are roughly classified into NOR type, NAND type, and AND type.
NOR type flash memories can be randomly accessed on a basis of one byte unit. However, when compared to NAND type and AND type flash memories, NOR type flash memories are expensive and have low integrated density.
On the other hand, since NAND type and AND type flash memories are low-cost and have high integrated density when compared to NOR type flash memories, those flash memories are widely used. For example, TH58512FT (TOSHIBA) is known as one of AND type flash memories.
However, the ratios of defective memory blocks (memory blocks which cannot store data correctly) included in all the memory blocks constituting the memory areas of the NAND type and AND type flash memories are intolerably large.
Accordingly, in many cases, when addressing a plurality of NAND type (or AND type) flash memories in parallel to write same data, writing cannot be correctly performed.
Therefore, in order to write same data in a plurality of NAND type (or AND type) flash memories, data is written in the plurality of NAND type (or AND type) flash memories one by one in a sequential order, using a control signal such as a chip enable signal.
However, the above method is inefficient, and if NAND type (or AND type) flash memories in which data is to be written are existing in a large number, quite a long time is required to complete writing.
Therefore, it has been quite difficult to mass produce products including NAND type (or AND type) flash memories in which predetermined data is preinstalled.